Robot arm mechanism and rotary joint apparatus

1. A robot arm mechanism in which a columnar support section having a turning rotary joint is supported on a base, an up/down section having an upward/downward rotary joint is mounted on the columnar support section, a linear extension and retraction mechanism comprising an arm section having linear elasticity is provided in the up/down section, a wrist section to which an end effector is attachable is mounted at a tip of the arm section, and at least one rotary joint for changing a posture of the end effector is mounted in the wrist section, wherein:

the arm section comprises:

a plurality of first pieces having a plate shape that are bendably connected, and

a plurality of second pieces having an inverted C-shape or hollow square shape in transverse section that are bendably connected on a bottom face side, with the first pieces and second pieces being formed into a columnar body whose bending is restricted and which is made rigid when the first pieces are joined to the second pieces on a surface side that is opposite to the bottom face side, and the first pieces and second pieces being returned to a bent state when the first pieces and second pieces are separated from each other;

the up/down section comprises:

a pair of side frames that are mounted on a rotating section of the turning rotary joint,

a cylindrical body that is supported in an axially rotatable manner by the side frames,

a motor unit including a motor and a gearbox for rotationally driving the cylindrical body,

a connecting section for connecting with an arm support body of the linear extension and retraction mechanism that movably supports the arm section, and

a guide structure that guides the second pieces that are separated from the first pieces into the columnar support section;

the motor unit, the connecting section and the guide structure are integrated with the cylindrical body;

the motor unit is housed inside the cylindrical body, and an output shaft of the motor unit is connected to one of the side frames;

the connecting section is fixed to an outer circumferential surface of the cylindrical body; and

the guide structure is an annular body that is provided on the outer circumferential surface of the cylindrical body.

2. The robot arm mechanism according to claim 1 , wherein the annular body is supported in a freely rotatable manner on the cylindrical body.

3. The robot arm mechanism according to claim 1 , wherein the annular body is a sliding belt which is mounted on the outer circumferential surface of the cylindrical body and which causes the second pieces to slide.

4. A rotary joint apparatus, comprising:

a fixed section;

a cylindrical body that is supported in an axially rotatable manner by the fixed section;

a motor unit including a motor and a gearbox for rotationally driving the cylindrical body; and

a linear extension and retraction mechanism connected to an outer circumferential surface of the cylindrical body,

wherein:

the motor unit is integrated with the cylindrical body; an

the motor unit is housed inside the cylindrical body, and an output shaft of the motor unit is connected to the fixed section,

wherein the linear extension and retraction mechanism comprises:

a plurality of first pieces that are bendably connected; and

a plurality of second pieces that are bendably connected, and

wherein:

the first pieces and second pieces are formed into a columnar body whose bending is restricted and which is made rigid, when the first pieces are joined to the second pieces;

the first pieces and second pieces are returned to a bent state, when the first pieces and second pieces are separated from each other; and

the second pieces separated from the first pieces is guided to the outer circumferential surface of the cylindrical body.